When 13 horses line up for Saturday's Preakness, horse racing will hold its collective breath.




The sport absorbed a devastating blow two weeks ago at the 134th Kentucky Derby, when Eight Belles suffered a fatal breakdown moments after she finished second to champion Big Brown.




It was the third death in two years of a thoroughbred who had run in a high-profile race &

the others being Barbaro, months after his 2006 Preakness injury, and George Washington in last year's Breeders' Cup Classic. The American Society for the Prevention of Cruelty to Animals called Eight Belles' injury and on-track euthanization "sad proof of the stress and rigors equines are forced to undergo in the racing industry."




The Derby incident has prompted outrage, debate and questions about why thoroughbreds seem to be breaking down more frequently &

doping, training, breeding and gender are the prime suspects &

and whether anything can be done about it.




In an initial response, the powerful Jockey Club announced May 8 that it had established a seven-member Thoroughbred Safety Committee.




Alex Waldrop, chief executive of the National Thoroughbred Racing Association, the lobbying and public relations arm of the industry, greeted the action by saying, "The industry's No. — priority is the health and safety of the horse."




So far, however, the industry has struggled to agree even on the scope of the problem, much less on its causes or possible solutions. For example, there are currently no uniformly recognized statistics for on-track deaths.




One industry committee, headed by Florida racetrack veterinarian Mary Scollay, found 2.03 deaths per 1,000 starts on dirt tracks like the one at Churchill Downs. "Saturday (Derby day) doesn't reflect my experience with thoroughbred racing," Scollay said. "I am there every day, and I see how many horses do race safely."




Nationally, that translates to hundreds of thousands of starts that end safely and several thousand that don't.




Bloodhorse.com, a leading racing Web site, has cited a slightly lower thoroughbred fatality rate of roughly 1.8 deaths per 1,000 starts in a study of California, Kentucky and Canadian tracks.




"We want this figure to be zero," said C. Wayne McIlwraith, director of equine orthopaedic research at Colorado State University.




Whatever the precise totals, isolating the biggest threat to thoroughbreds is difficult. Some observers say fillies should not race against colts, or that today's 2- or 3-year-olds aren't mature enough or trained sufficiently to compete at distances of a mile or more.




McIlwraith told Bloodhorse.com that there is no data to suggest females suffer more catastrophic injuries than males. Nor, he said, is there any evidence that 2-year-olds are injured more than 3- or 4-year-olds. Four-year-olds actually have the highest incidents of catastrophic injuries, he said.




Added Bob Baffert, who has trained winners in eight Triple Crown races: "It's not even an issue. I come from the world of quarterhorses. There, the fillies beat up on the boys all the time."




Rick Arthur, the equine medical director for the California Horse Racing Board, said fitness is the real issue.




"When a 3-year-old gets to the Kentucky Derby, it becomes a real test of stamina," he said. "The bones are ready, but they have never run a mile and a quarter. That's what makes it such a test."




Barbara Vanlangendock, a Florida bloodstock agent, said, "You have to look at the animals individually. I have tons of owners who don't race their horses until they are four."




The New York Times recently cited statistics that addressed the relative durability of horses. It said that, in 1960, thoroughbreds made an average of 11.3 racing starts in their career. Last year, that average was 6.3.




Arthur said that North America has gone increasingly toward the shorter races, six- and seven-furlong dashes, because horses are bred for that now.




"For a long time, the thoroughbred was bred as a horse that can go the distance and take your breath away," said Tom Bowman, general manager and partner of Northview Stallion Station in Chesapeake City, Md. "We are starting to sacrifice some of those qualities for a short racing career and cheap speed overall."




Arthur pointed out that the June 7 Belmont Stakes will be the only time a 3-year-old will go a mile and a half in this country. That is one difference from foreign racing, he said, where breeding leans more toward durability.




Another major difference involves doping. Horses may run at North American tracks 24 hours after being given therapeutic drugs such as Lasix or Butazolidin. (Lasix is a diuretic that treats bleeding and reduces blood pressure; Butazolidin, or Bute, is an analgesic and anti-inflammatory.) Such doping is banned everywhere outside of North America. Critics say these drugs can mask injuries and contribute to breakdowns.




Others point to genetics, suggesting that thousand-pound thoroughbreds &

the product of just three original stallions, 43 mares and generations spanning 300 years &

have become so inbred they are irreversibly fragile.




"We certainly debilitated the breed," said Nick Zito, a two-time Kentucky Derby winning trainer whose Stevil will run in the Preakness. "We've been talking about that for 15 to 20 years. They don't make horses like they used to, right or wrong. ... You look at the 2-year-olds of years ago. They ran them every week. They just don't make them like they did."




The issues of drugs and breeding seem intertwined. Many say that the animals are now too large for their ever-thinning legs, causing chronic soreness. But the commercial pressure to run them has brought the allowance of Lasix and Bute, and has also enticed some trainers to slip into illegal use of anesthetics.




As controversial as the legal use of Lasix and Bute is, even more so is the alleged use by some trainers of illegal analgesics, especially Mepivacaine. According to Arthur, that deadens the injured area, allows horses to run, but takes away the pain that is the best warning to both horse and trainer that something is wrong.